PASADENA, Calif.—A U.S. citizen accused of attempting to bomb the Vietnamese Embassy in Bangkok should not be extradited to Thailand because he was part of an uprising against a repressive government, the man’s attorney argued Monday before a federal appeals court.

The actions of Van Duc Vo, who fled communist Vietnam in 1978, fall under a “political offense” exception to extradition, attorney Michael Mayock told a three-judge panel of the 9th U.S. Circuit Court of Appeals. About 200 supporters waved South Vietnamese and U.S. flags outside.

Mayock also argued that Thailand would be under pressure to transfer Vo to Vietnam, where he would likely face execution.

The 9th Circuit panel was not expected to rule on the issue for about two months.

Vo, 45, has become a hero to some Vietnamese in exile as a member of a group dedicated to overthrowing the Southeast Asian nation’s communist government. He has been charged in Thailand, a strong U.S. ally, with “conspiring to use and using weapons of mass destruction during an attempted bombing” of the Vietnamese Embassy on June 19, 2001.

Vo maintains he planted two bombs as a political act that was part of an uprising against Vietnam’s government—but defused the devices when he realized the U.S. Embassy was nearby.

Thai authorities allege that Vo placed a backpack full of explosives in front of the embassy in Bangkok and threw over the compound’s fence a box that contained 11 pounds of diesel fuel and ammonium nitrate. Notes were attached to both devices, which were supposed to be activated by cell phones, prosecutors said. Calls were made to the rigged phones, but the bombs didn’t go off.

Vo, a resident of Baldwin Park, was arrested after returning to the United States in October 2001. American officials later dropped U.S. charges and agreed to extradite him to Thailand.

During the hearing, the appeals panel—Judges Stephen Reinhardt, Alex Kozinski and Marsha S. Berzon—questioned whether the political offense exception would be applicable because the bombs were planted outside of Vietnam.

Reinhardt asked Mayock whether making that exception would cause “terrorism to be exported to other neutral countries.”

Mayock contended the exception did apply because the embassy is Vietnamese territory.

The judges also questioned whether the attempted bombing could not also be considered a crime against Thailand although it was on Vietnamese territory.

“Suppose you blow up the Romanian Embassy in Washington? Would that be an offense against U.S. law and wouldn’t it occur in the U.S.?” Reinhardt asked.

Mayock asserted that although Vo had become a U.S. citizen, he is still considered a Vietnamese citizen by Vietnam’s government, making his action fall under the political offense exception.

“If he is a U.S. citizen getting involved in an uprising,” asked Kozinski, “how is it different from him picking an uprising in any other country?”

Mayock also argued that because the United States initially brought its own charges against Vo, extradition would violate the treaty because he had already faced U.S. proceedings.

Assistant U.S. Attorney Daniel Goodman argued that it was up to Secretary of State Condoleeza Rice, not the judges, to apply discretion as to whether Vo should be extradited.

Goodman also countered the claim that Vo could end up in Vietnam by arguing that such a transfer would violate the U.S treaty with Thailand on extradition.

“There’s no reason on the record that Thailand would do that,” Goodman said.

“But there’s been no guarantee of that,” said Kozinski.

Vo is a member of the Government of Free Vietnam, a group run by several exiles who claim to have set up military training camps on Vietnam’s border and vow to liberate their homeland. He remains in custody in a federal detention center in Los Angeles.

Chanh Nguyen, founder of the Government of Free Vietnam, was among those demonstrating outside the 9th Circuit’s Southern California chambers. He said the Sept. 11, 2001, terrorist attacks have colored Vo’s case.

“Now the judges in the case, every time they mention about 9/11 and the terrorist situation, but he’s not terrorist, he’s a freedom fighter,” Nguyen said.

Duc-Khue Nguyen, 49, came with her 80-year-old mother to support Vo.

“Even though we became naturalized as U.S. citizens, our souls are still Vietnamese,” Nguyen said. “We have to act, we have become the mouthpiece for Vietnamese because the people there cannot speak up.”